Well designed product and the Espruino IDE results in a fast and efficient workflow. My main complaint is that the product was shipped with an old firmware and was basically useless prior to being updated. Once I found a video clip on YouTue on how to update it worked nicely with my Chromebook.
I couldn't get it working with my Windows laptop however and because of that I would have preffered to have a micro USB connector on the puck.js. That would hopefully also make it easier to work with BLE as you then could use the IDE for programmnig without interferring with Blueooth.
Despite this I still think this is an excellent little device.